Well, yes, just as you can cut your own hair—in other words, there is nothing stopping you, but the outcome might not be what you wished! There is nothing in Wisconsin law that requires you to have your will prepared by an attorney. However, if you want to make sure that your will is valid, that it complies with the law and does exactly what you intend it to, your best bet is to work with an attorney who is familiar with Wisconsin estate planning law. If you tell your attorney what you are trying to accomplish, she may also be able to recommend other estate planning tools, such as trusts and transfer-on-death deeds, that will be better suited to accomplish your estate planning goals.
If your will is unclear, incomplete or invalid, your heirs may end up fighting, in and out of court. Not only will you not have achieved your estate planning goals, you may inadvertently cause family rifts that might never heal. The relatively small cost of having an experienced professional draw up your will is almost always worth it.